Gear train mechanism



R. M. MANNING 2,709,923

GEAR TRAIN MECHANISM June 7, 1955 Filed Sept. 3, 1954 invenror': RalphM. Manning His AHor ney GEAR TRAIN MECHANISM Ralph M. Manning, WestMedford, Mass., assignor to General Electric Company, a corporation ofNew York Application September 3, 1954, Serial No. 454,120

7 Claims. (Cl. 74-421) Briefly, the invention comprises a plurality ofintermeshing gear assemblies, each assembly of which includes a pair ofgears of different diameters mounted for rotation between a pair ofspaced members. All of the gear assemblies are alike and each hasidentical shaft portions embodying a novel step-like configurationcooperating I.

with suitable apertures provided in the mounting members. The aperturesrange in diameter so that each receives a different portion of the shafttherein whereby individual pairs of gears are located at successivelygreater distances from one of the spaced mounting members, or atsuccessively smaller distances from the other mounting member, dependingof course upon which is selected as a reference. In this way, thenecessary lateral spacing is achieved to permit proper intermeshing ofthe gears and at the same time provide adequate clearances for properoperation.

Since all gear assemblies are identical, it is possible to lowermanufacturing costs through greater availability of mass productiontechniques, the reduction in tool costs, the ease of assembly, and thepossibility of substantially reduced inventories of spare andreplacement parts.

The invention, its objects and the benefits and advantages to be derivedtherefrom, will be best understood upon reference to the detaileddescription set forth below, particularly when taken in conjunction withthe sheet of drawings annexed hereto, in which Fig. 1 is a top-view,partly in section, of the novel gear train covered hereby, and Fig. 2 isa fragmentary view, in elevation, of the arrangement shown in Fig. 1. Inboth Figs 1 and 2, the views show the mounting means in addition to thegear assemblies.

Referring first to Fig. 1, wherein like parts will be assigned likenumbers, we see a plurality of intermeshing gear assemblies 3 formingthe gear train 4 by which motion imparted to the driving pinion 5 can betransmitted and reduced to the driven gear, a portion of which is shownat 6. In the embodiment shown the speed of the driving pinion is reducedby the gear train but it is to be understood that the gear train hasequal application to arrangements requiring a step-up in the outputspeed.

The gear assemblies 3 are all identical and for the sake of clarity onlyone set of numerals will be applied to the drawings, and utilized in thedescriptive material following. Thus each gear assembly 3 includes apair of gears 7, 8 having different diameters and arranged injuxtaposition with respect to shaft means 9, 11 extending outwardly fromthe outer face of each gear. The shafts 9, 11 are identical save for thebearing hub 12 arranged contiguous to the outer face of gear 7. That is,each of the shafts 9, 11 have identical portions, both of which haveprogressively decreasing diameters by reason of the nited States Patent2 plurality of successively arranged cylindrical sections 13, 14, 15, 16of progressively decreasing diameter.

The gear assemblies 3 thus include the gear pair 7, 8 as well as theshafts 9, 11 and one convenient and practical method of fabricatingthese assemblies is to mold them as a one piece assembly from somesuitable material. It has been found that nylon is quite practicalalthough the invention is not limited to such material, nor for thatmatter, need the gear assembly be a one piece unit.

The gear assemblies are mounted for rotation between a pair of suitablespaced members in the form of the spaced plates 17, 18. These plates maybe part of a device embodying the gear train as a component part and maybe rigidly mounted with respect to each other by means of the threadedspacer members 19 and cooperating nuts 21. The driving and driven gears5, 6 are also suitably journalled for rotation in the plates 17, 18.

Cooperating with shafts 9, 11, there is arranged a series of oppositelydisposed apertures in each of the plates 17 18, the row in plate 17being of sucessively increasing diameter, starting with the smallest at22 and progressing upwardly through 23 and 24, the largest being shownat 25. The row in plate 18 has the largest aperture 25 arranged oppositethe smallest aperture 22 in plate 17, the succeeding aperturesdecreasing in diameter through 24 and 23', the smallest being shown at22.

The large apertures 25, 25 are dimensioned to receive the shaft section13, the next largest 24, 24 to receive section 14, the second nextlargest to receive section 15, and the smallest 22, 22 to receive thesmallest shaft section 16. Thus, with the apertures being reverselyarranged, it is immediately apparent that at the left-hand gear trainextremity, most of the shaft 11 projects outwardly from the plate 18whereas at the right-hand extremity, most of the shaft 9 projectsoutwardly from the plate 17. The step-by-step arrangement of the partsplaces the left-hand gear pair closest to plate 18 so that its largergear can mesh with the driving pinion 5. In the next position, the gearpair are not as close to plate 18 as the first gear pair so its largegear can mesh with the small gear of the first pair. The other two gearassemblies are, in a like manner placed successively and progressivelyfurther away from plate 18 to allow proper intermeshing of the completetrain. The shoulders formed at the junctions of the shaft sectionsprovide bearing surfaces against the plates 17, 18, the hub 12 beingprovided for a bearing surface immediately between extreme left-handgear 7 and plate 18 instead of having the gear itself abut the innerside of the plate.

For assembly of the gear train, it is only necessary to drop the gearassemblies in place on one mounting plate and then drop the othermounting plate in place over the other shaft extremities, after whichthe plates are secured together. The driving and driven gears will beadded to the assembly in any convenient manner. While the embodimentshown illustrates a gear train comprising four identical gearassemblies, it is to be understood that the invention has equalapplication to other numbers of gear assemblies.

Thus, there is provided a novel gear train that is ideally adapted formass production techniques by reason of the use of pluralities ofidentical interchangeable parts. Such design permits minimum tool costs,minimum inventory requirements and maximum ease of assembly andservicing. All of the above contributes to low cost manufacturing notheretofore available for mechanisms of this kind.

Therefore, while a particular embodiment of the subject invention hasbeen shown and described herein, it is in the nature of descriptionrather than limitation, and it will occur to those skilled in the artthat various changes, modifications, and combinations may be made 3within the province of the appended claims, and without departing eitherin spirit or scope from this invention in its broader aspects.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

l. A gear train comprising a plurality of rotatably mounted intermeshinggear assemblies, each of said gear assemblies having supporting shaftsextending outwardly from both sides thereof, each of said shafts havingoutwardly progressively decreasing diameters, and mounting means forsaid gear assemblies, said mounting means including a pair of spacedmembers between which are located said gear assemblies, said spacedmembers having a series of oppositely disposed apertures for receivingtherein said shafts, said apertures having progressively decreasingdiameters and being reversely arranged whereby the largest diameter inone series is opposite the smallest diameter in the other series.

2. A gear train comprising a plurality of rotatably mounted intermeshinggear assmblies, said assemblies including a pair of gears of differentdiameters, supporting shafts for each of said gear assemblies havingportions extending outwardly from opposite sides thereof, all of saidportions on one side of said assemblies being of equal length and ofoutwardly successively decreasing diameter, and mounting means for saidshafts including a pair of spaced members between which said gearassemblies are located, said members having a series of oppositelydisposed apertures therein for receiving said shafts, the apertures inone of said series having diameters successively decreasing through saidrange of diameters of said shaft portions whereby at one end of saidseries a greater length of said shaft projects through its cooperatingaperture than at the other end of said series.

3. A gear train comprising a plurality of rotatably mounted intermeshingidentical gear assemblies, each of said gear assemblies having shaftportions of equal length extending outwardly from opposite sidesthereof, said shaft portions having successive sections of outwardlydecreasing diameter, and mounting means for said gear assemblies, saidmounting means including a pair of spaced members between which arelocated said gear assemblies, said spaced members having a series ofoppositely disposed apertures for receiving therein predeterminedsections of said shafts, said apertures having successively decreasingdiameters and being reversely arranged in said members whereby thelargest diameter in one series is opposite the smallest diameter in theother series.

4. A gear train comprising a plurality of rotatably mounted intermeshingidentical gear assemblies, said assemblies including a pair ofjuxtaposed gears having different diameters, shaft means extendingoutwardly from each side of said gear assemblies, said shaft meanshaving identical portions of progressively decreasing diameter, andmounting means for said shafts including a pair of spaced plates betweenwhich said gear assemblies are located, each of said plates having aseries of oppositely disposed apertures therein to receive therethroughportions of said shafts, said apertures having progressively decreasingdiameters and being reversely arranged whereby the largest diameter inone series is opposite the smallest diameter in the other series.

5. A gear train comprising a plurality of rotatably mounted intermeshingidentical gear assemblies, said assemblies including a pair ofjuxtaposed gears having different diameters, each of said assemblieshaving shaft portions of equal length extending outwardly from oppositesides thereof, said shaft portions having successive sections ofoutwardly decreasing diameter, and mounting means for said gearassemblies, said mounting means including a pair of spaced platesbetween which are located said gear assemblies, said plates having aseries of oppositely disposed apertures for receiving thereinpredetermined sections of said shafts, the diameters of oppositeapertures being such that at one end of said series one of said shaftportions projects outwardly from one of said plates and at the other endof said series another of said shaft portions projects outwardly fromthe other of said plates.

6. A gear train comprising a plurality of rotatably mounted intermeshingidentical gear assemblies, said assemblies including a pair ofjuxtaposed gears of difierent diameter, supporting shafts for each ofsaid gear assemblies, said shafts having successive sections ofoutwardly decreasing diameter and mounting means for said shaftsincluding a pair of spaced members between which are located said gearassemblies, said members having a series of oppositely disposedapertures therein for receiving therethrough portion of said shaftmembers, one row of said apertures having successively decreasingdiameters and the other row of said apertures having successivelyincreasing diameters, said diameters varying through the range invariation of said shaft diameters whereby individual pairs of gears arelocated at successively increasing distances from one of said mountingmembers.

7. A gear train comprising a plurality of rotatably mounted intermeshingidentical gear assemblies, said as semblies including a pair ofjuxtaposed gears of different diameter, supporting shafts for each ofsaid gear assemblies extending outwardly from opposite sides thereof,each of said shafts having an outwardly converging steplikeconfiguration wherein is provided successive sections of decreaseddiameter, and mounting means for said shafts including a pair of spacedplates between which are located said gear assemblies, said plateshaving a series of oppositely disposed apertures therein cooperatingwith said shafts, one row of said apertures having successivelydecreasing diameters and the other row of said apertures havingsuccessively increasing diameters whereby the shaft section of greatestdiameter extends through the plate apertures of greatest diameter andsuccessive shaft sections of reduced diameter extend through successiveapertures of reduced diameter.

No references cited.

